Lock assembly



March 21, 1961 v. MUTTART 2, 7 2

LOCK ASSEMBLY Filed July 23, 1957 1 1.

2 Sheets-Sheet 1 INVENTOR MATTORNEY M r h 2 1 61 v. MUTTART 2,976,072

LOCK ASSEMBLY Filed July 25, 1957 2 Sheets-Sheet 2 INVENTOR Vb'naeni Ma 2, fart fiToRM-w LOCK ASSEMBLY Vincent Muttart, Downey, (Ialifi, assignor to Independent Lock Company, Fitchburg, Mass., a corporation of Massachusetts Filed July 23, 1957, Ser. No. 673,591

1 Claim. (Cl. 292-41363) This invention relates to cylindrical locks, and particularly to cylindrical locks of the type known as exit locks by reason of their frequent use upon the front doors of houses. More particularly, this invention relates to a cylindrical exit lock with a latch aperture assembly, knob operated from the inside and provided with a novel thumb lever mechanism for operation from the outside.

Still more particularly, this invention relates to a cylindrical exit lock having mounted on the inside door face a latch operating knob and a dogging pushbutton or turnbutton and having mounted on the outside door face a novel thumb lever mechanism controlling the latch bolt when the' pushbutton or turnbutton is in undogged position, and a key controlled mechanism capable of withdrawing the latch bolt independently of the position of the pushbutton or turnbutton.

This invention relates further to an assembly as above described which includes a rapidly demountable escutcheon plate.

As this invention is particularly well adapted for use with a cylindrical lock assembly in accordance with my copending application Serial No. 645,774, filed March 13, 1957, I have illustrated my invention as used in conjunction therewith, but it should be understood thatmy invention may be adapted to various other lock assemblies, without departing from the spirit thereof.

Known to me are various lock assemblies employing a thumb lever as the mode of withdrawing the latch bolt. While no purpose would be served in now reviewing such known assemblies, I shall summarize the disadvantages most commonly experienced in their use.

Since it is at once apparent that the throw or arcuate distance which a thumb actuated lever can travel is relatively small as compared with the circumferential distance normally travelled by a rotating knob, some magnification of movement has heretofore been necssary to adapt a cylinder lock to thumb operation. Such magnification has frequently been accomplished by providing a thumb lever assembly with a fractional mechanical advantage. The disdvantages of such arrangement are obvious since the counterforces, such as latch bolt spring pressure and sliding friction, operating to retard latch Withdrawal, are magnified. To overcome such magnified forces, it is necessary to exert thumb pressures, sometimes of a magnitude to render normal operation painful and diflicult, if not impossible, particularly to some women and children.

A further fault commonly found in conventional thumb operated latch assemblies is the cumbersome and costly structure provided for communicating thumb leverage to the latch bolt assembly. Aside from the increased expense attendant upon producing such assemblies, I have determined that additional frictional resistance is encountered, thereby contributing further to the problem previously noted.

It has been common in known assemblies to provide the thumb lever with an individual spring for returning Fatented Mar. 21, 19,61

such lever to its normal position. It will be apparent that an assembly utilizing such spring will be more d-ifiicult to use than if such spring were eliminated.

Known assemblies of the type described have been commonly handed for use upon either right hand or left hand opening doors, it being necessary for the manufacturer to provide, and the distributor to maintain, quantities of each of the two types of assemblies.

It is accordingly an object of my invention to provide a thumb operated lock assembly wherein the pressure needed for bolt retraction is minimized by allowing the use of a multiplying mechanical advantage for the thumb lever. A further object of my invention is to provide a thumb actuated lock assembly utilizing a simple friction minimizing link between the thumb lever and the latch bolt retracting assembly.

Still a further object of my invention is to provide an assembly wherein gravitational forces are advantageously employed and, in a measure, eliminate the necessity for additional springs to return the thumb lever to the normal position, the projecting springs utilized to operate the latch bolt being adapted primarily to perform this function and effect economies in installation and assembly.

Still another object of my invention is to provide a thtunb actuated lock assembly which, by simple adjust ment of the parts, may be adapted to be-handed for use on either a right hand or a left hand opening door.

Another object of my invention is to provide a quickly demountable escutcheon for an assembly of the type described.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, I make reference to the accompanying drawing forming a part hereof, in which:

Figure 1 is a front elevation of the outer portion of my device, as it appears in operation;

Figure 2 is a magnified section taken on the line 22 of Figure l;

Figure 3 is a magnified fragmentary plan'view of an escutcheon plate in accordance with my invention;

Figure 4 is a magnified section taken on the line 4-4 of Figure 1;

Figure 5 is a section taken on the line 5-5 of Figure 4;

Figure 6 is a section taken on the line 6-6 of Figure 4.

For convenience in understanding my invention, reference is made to my copending aforementioned application to exemplify a rotationally actuated, spring pro- 'ected latch bolt assembly with which my thumb lever mechanism may be employed, and with which the specific thumb operated mechanism is particularly valuable in transposing movements of small magnitude to effect substantial retraction movement readily.

In the novel thumb operating assembly to which this invention is directed, a lever 19, having an exterior thumb actuated branch 11 and an interior branch 12 is pivoted about a fulcrum 13 supported on the outer escutcheon casing and integral handle H aflixed to the outer face of the door.

'The interior branch 12 extends inwardly to engage a seat 4 formed transversely through a communicating plate 15. The plate 15 is guided to be slidable in a vertical plane by the shoulders 16, 17, 18 and 19 defined by the casing. The plate 15'has an extended recess 2%) formed therethrough asymmetrical to the vertical axis and comprising a large central clearance por- 7 erally as A, is provided with an outer plate 25 from which extends the upturned lugs 26 and 27. It should be understood that rotation of the plate 25 serves to withdraw the latch bolt, the operation of said withdrawal being more fully described in my copending application heretofore referred to, as an example of a rotary transmission expedient which is preferred because of the novel motion magnifying relationship.

The latch bolt may likewise be withdrawn by the action of the independently, concentrically located spindle 28 which is operatively connected to the key plug assembly B, as shown in my aforesaid prior filed application.

It should be noted that when the lock assembly is dogged by actuation of the push button dogging assembly, generally referred to as C, latch bolt withdrawal may be effected only by operation of the key plug assembly B, it being understood that the thumb actuating assembly is useful only when the pushbuttou C is in the undogged position shown in Figure 2. In this position, depression of the thumb branch 11 pivots the lever 10 about the fulcrum 13, swinging the branch 12 arcuately upward. The above action serves to impart a vertical upward sliding movement to the plate 15 (see the arrow, Figure sidewise slipping of the plate being prevented by the action of the four guide shoulders 16, 17, 18 and 19. Upward movement of the slide plate 15 communicates to the actuating plate 25 a rotary motion, due to the coaction of the shoulder 24 with the lug 27, thereby operating the latch retractor mechanism A and withdrawing the latch bolt. The lug 26 is permitted, by the nature of the lug clearance recess 21, to swing freely during said upward movement, without interference from the periphery of the walls defining the said recess.

It should be noted that the recess 21 is formed with an extended central portion to provide for the passage through the recess of portions of the key plug assembly, said recess being of a size to prevent contact of the plate 15 with any portion of the plug assembly B, yet limiting the eccentricity of the slide plate 15 and lug on the plate 25 to prevent binding.

As heretofore mentioned, it is often necessary to change the banding of the door lock assembly. In order to accomplish such change, it is merely necessary to remove the plate 15 from the escutcheon assembly and rotate it 180 about its vertical axis, again positioning the seat 14 over the inner branch 12. In this inverted position, it will be noted that the shoulders 22, 2'4 will now envelope the lug 26 and the shoulder 23 abuts the lug 27. When the thumb is depressed with the plate thus reversed, the inner plate will be rotated in the direction opposite to that in which it moved with the plate 15 in the former position, and the handing of the door thus easily changed.

The inside escutcheon of my assembly is adapted to be quickly demounted without running the risk of scuffing or scratching. To provide such quick demountability, the escutcheon plate 30 is frictionally, resiliently rotated on a seat 31, secured to the inner face of the door. An abutment 32 extends outwardly from a portion of the inner latch mounting base 33. The escutcheon plate 30 is provided with an inwardly extending collar 34, having a shoulder 35 defined by a recess formed in the wall thereof. The shoulder 35 and the abutment 32, in the mounted position of the plate, are in approximately superimposed, transversely separated position, thereby permitting the insertion therebetween of a pry or lever L (see Figure 2), such as the bit of a screw driver.

It will be readily recognized that when such pry or lever L is inserted and twisted, the escutcheon plate 30 will be forced transversely outwardly, thereby quickly demounting it from the seat 31.

By this construction, an etficient, decorative and inexpensive thumb operated assembly is provided, having the advantages of smooth and easy operation, with minimal friction and wear.

By obviating the necessity for separate spring biasing operation on a motion magnifying lever, my assembly facilitates thumb actuation to the point where persons with only limited strength are able facilely to withdraw the latch bolt and in no case does the lever assume a dead center position.

The readily changeable or reversible handing feature permits the use of my assembly, without special tools, on doors which open in either direction, and obviates the necessity for supplying and storing latch assemblies limited to use on doors of either right or left hand.

The escutcheon demounting feature of my invention is adapted to facilitate an operation which formerly was not only time-consuming but was a frequent source of irritation by reason of the likelihood, in other assemblies, of marring the fine finish of the plate in removing the same. 7

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

In a thumb lever operable door lock assembly wherein an outwardly spring biased latch bolt is withdrawn by retractor means operatively connected to inner and outer retractor actuating plates arranged to be pivoted to retractor actuating position by means afiixable on the inner face of a door, means on the outer face of said door for withdrawing said bolt, comprising a vertically swingable lever having an exterior thumb operable branch and an internally extended branch forming a motion transmitting tooth, a vertically, slidably guided plate positioned in a casing with a seat operatively connected to said lever by the engagement of said tooth with said seat, thereby to actuate said plate in a vertical plane exterior of the outer face of the door upon thumb actuation of said lever, said plate including retractor plate engaging means whereby said bolt may be withdrawn by actuating said lever against the biasing action of said latch bolt spring, said plate being guided to be slidable vertically by guide shoulders defined by the casing and said plate having an extended recess asymmetrically positioned with respect to the vertical axis of said plate comprising a large clearance portion whose upper edges provide a pair of spaced upper lateral shoulders and one lower lateral shoulder spaced in opposed position to one of said upper edges, a pair of retractor lugs rotatably carried by said outer retractor plate extending through said recess, one of which lugs may be selectively extended between the upper and lower opposed lateral shoulders,

the other of said lugs lying in contact with the other upper lateral shoulder, whereby lever operation will transmit one-direction rotary movement between the one of said lugs and the said opposed shoulders of said plate to actuate the said outer retractor plate and, upon release of said lever, said other lug will engage said other shoulder to limit the return of said lever to normal position.

References Cited in the file of this patent UNITED STATES PATENTS 1,735,914 Wread Nov. 19, 1929 1,843,143 Rymer Feb. 2, 1932 1,944,470 Schlage Jan. 23, 1934 2,147,581 Prinzler Feb. 14, 1939 2,266,106 Voight et al. Dec. 16, 1941 2,423,206 Schlage July I, 1947 2,536,494 Erkkila Jan. 2, 1951 2,844,953 Hillgren July 29, 1958 km k 

